JP2016048205A - Radio wave transmitter positioning system, radio wave transmitter positioning device, and radio wave transmitter positioning method - Google Patents

Abstract

In a radio wave transmitter positioning system in which radio waves transmitted from a moving transmitter are received by a plurality of receivers, and the transmitter is positioned from the radio field intensity received by each receiver, the plurality of receivers from the same plane. It is possible to prevent the difference in altitude from being mixed into the positioning error and perform positioning with higher accuracy. A receiver DB stores receiver information including three-dimensional coordinates of the position of each receiver. The positioning processing unit 101 obtains the observation distance between each receiver 120 and the transmitter 110 based on the radio wave intensity received by each receiver 120. Then, the positioning processing unit 101 calculates 3 of the position of the transmitter 110 based on the obtained observation distance and the three-dimensional coordinates of the position of each receiver 120 included in the receiver information stored in the receiver DB 106. Find the dimensional coordinates. [Selection] Figure 1

Description

  The present invention relates to a radio wave transmitter positioning system, a radio wave transmitter positioning device, and a radio wave transmission that receive radio waves transmitted from a moving transmitter by a plurality of receivers and position the transmitter from the radio wave intensity received by each receiver. It relates to the positioning method.

  General use of the US Global Positioning System (GPS) has been lifted, and map coordinates at any point can be measured. GPS is installed in navigation systems and portable terminals, and is an indispensable function in daily life. However, GPS is limited to the outdoors where a plurality of GPS satellite radio waves can be captured. Therefore, sufficient accuracy cannot be obtained underground or indoors.

  As a method for realizing indoor positioning instead of GPS, IMES (Indoor Messaging System) in which a transmission source of the same system as GPS is installed indoors, position measurement by radio waves such as Wi-Fi and Bluetooth (registered trademark), Position positioning by LED illumination, autonomous navigation (Dead Reckoning), positioning by special voice, and the like have been proposed. These are generally methods for measuring the position of a terminal that receives sensor information. In other words, this is a method of positioning the position of the moving receiver.

  On the other hand, as in the wireless communication system disclosed in Patent Document 1, it is also conceivable that the results of receiving a moving radio wave source with a plurality of receivers are collected on a server and positioned. . Hereinafter, this positioning method is referred to as transmitter positioning.

JP 2010-74700 A

  In the wireless communication system described in Patent Document 1, the receiver and the transmitter are related on a two-dimensional plane by a distance obtained from the received radio wave intensity. That is, in this wireless communication system, it is considered that all receivers and transmitters are arranged on the same plane. For this reason, in actual operation, an elevation difference from the same plane of each receiver is included in the positioning error.

  An object of the present invention is to prevent an elevation difference from the same plane in a plurality of receivers from being mixed into a positioning error, and to perform positioning with higher accuracy, a radio wave transmitter positioning system, a radio wave transmitter positioning device, and a radio wave It is to provide a transmitter positioning method.

In order to achieve the above object, the radio wave transmitter positioning system of the present invention includes:
A radio wave transmitter positioning system that receives radio waves transmitted from a moving transmitter by a plurality of receivers and obtains the position of the transmitter from the radio wave intensity received by each receiver,
A receiver table storing receiver information including the three-dimensional coordinates of the position of each receiver;
An observation distance calculation means for obtaining an observation distance between each receiver and the transmitter based on the radio field intensity received by each receiver;
Three-dimensional coordinates of the position of the transmitter based on the observation distance obtained by the observation distance calculation means and the three-dimensional coordinates of the position of each receiver included in the receiver information stored in the receiver table Transmitter position estimation means for obtaining
It is characterized by providing.

Preferably, the radio wave transmitter positioning system of the present invention is
A transmitter table in which transmitter information including a known height of the transmitter is stored;
The transmitter position estimating means uses a known height of the transmitter included in the transmitter information stored in the transmitter table as one of the three-dimensional coordinate values of the transmitter position. As the initial value of the height, the other two coordinate values are obtained.
It is characterized by that.

Preferably, the radio wave transmitter positioning system of the present invention is
The number of the receivers that have received the signals of the transmitters to be positioned in a certain period is three or more.

Moreover, the radio wave transmitter positioning device of the present invention is
A radio wave transmitter positioning device used in the radio wave transmitter positioning system described above,
A receiver table storing receiver information including the three-dimensional coordinates of the position of each receiver;
An observation distance calculation means for obtaining an observation distance between each receiver and the transmitter based on the radio field intensity received by each receiver;
Three-dimensional coordinates of the position of the transmitter based on the observation distance obtained by the observation distance calculation means and the three-dimensional coordinates of the position of each receiver included in the receiver information stored in the receiver table Transmitter position estimation means for obtaining
It is characterized by providing.

Moreover, the radio wave transmitter positioning method of the present invention includes:
A radio wave transmitter positioning method in which radio waves transmitted from a moving transmitter are received by a plurality of receivers, and the position of the transmitter is obtained from the radio wave intensity received by each receiver,
An observation distance calculation step for obtaining an observation distance between each receiver and the transmitter based on the radio wave intensity received by each receiver;
Based on the observation distance obtained in the observation distance calculation step and the three-dimensional coordinates of the position of each receiver included in the receiver information stored in the receiver table, the three-dimensional coordinates of the position of the transmitter are obtained. A desired transmitter position estimating step;
It is characterized by providing.

  ADVANTAGE OF THE INVENTION According to this invention, it can prevent that the elevation difference from the same plane in several receivers mixes in a positioning error, and can perform positioning with higher precision.

It is a figure which shows an example of a structure of the radio wave transmitter positioning system which concerns on embodiment of this invention. It is a figure which shows an example of a structure of the reception history table stored in reception history DB. It is a figure which shows an example of a structure of the transmitter table stored in transmitter DB. It is a figure which shows an example of a structure of the receiver table stored in receiver DB. It is a figure which shows an example of a structure of the positioning result table stored in positioning DB. It is the top view which looked at an example of the indoor where the transmitter and receiver were arranged from the upper part. It is the front view which looked at the same indoor as FIG. 6 from the front. It is a figure which shows an example of the relationship between the three-dimensional position and distance of a transmitter and four receivers. It is a figure which shows an example of the flow of the radio wave intensity information preservation | save process which preserve | saves the radio wave intensity information transmitted from each receiver in reception history DB. It is a figure which shows an example of the flow of the position estimation process which estimates the position of the transmitter in a certain time based on a reception history, and preserve | saves the positioning result information which shows the estimated position in positioning DB. FIG. 10B is a continuation of FIG. 10A.

  Hereinafter, a radio wave transmitter positioning system, a radio wave transmitter positioning device, and a radio wave transmitter positioning method according to embodiments of the present invention will be described with reference to the drawings. In all the drawings for explaining the embodiments, common constituent elements are denoted by the same reference numerals, and repeated explanation is omitted.

FIG. 1 shows an example of the configuration of a radio wave transmitter positioning system according to an embodiment of the present invention.
The radio wave transmitter positioning system includes a transmitter positioning device 100, a transmitter 110, and a plurality of receivers 120. The transmitter positioning device 100 and each receiver 120 are connected to the network 130 and can communicate with each other. The network 130 may be a wired network or a wireless network.
The transmitter 110 has a radio wave transmission function, and the receiver 120 has a radio wave reception function. That is, the transmitter 110 transmits a radio signal, and the receiver 120 receives the radio signal. The receiver 120 transmits radio wave intensity information including RSSI (Received Signal Indicator), which is the radio wave intensity at the time of reception, to the transmitter positioning device 100 via the information network 130.

The transmitter positioning device 100 includes a positioning processing unit 101, a reception processing unit 102, a receiving unit 103, a reception history DB (database) 104, a transmitter DB 105, a receiver DB 106, and a positioning DB 107.
The receiving unit 103 receives the radio wave intensity information transmitted by the receiver 120 and passes it to the reception processing unit 102. The reception processing unit 102 stores the radio signal strength information in the reception history DB 104. As will be described later, positioning processing unit 101 estimates the position of transmitter 110 at the time of radio wave transmission based on the information in each table stored in reception history DB 104, transmitter DB 105, and receiver DB 106. The positioning processing unit 101 stores the estimated position of the transmitter 110 in the positioning DB 107.
Note that the functions of the reception processing unit 102 and the positioning processing unit 101 can be realized by software processing by a computer or by hardware. When realized by software processing by a computer, each function of the reception processing unit 102 and the positioning processing unit 101 is realized by a CPU (Central Processing Unit) executing a predetermined program stored in the main memory. . In this case, the reception history DB 104, transmitter DB 105, receiver DB 106, and positioning DB 107 are stored in the storage device of the computer. The receiving unit 103 is hardware including a network interface, but some of the functions can also be realized by software processing by a computer.

FIG. 2 shows an example of the configuration of the reception history table 200 stored in the reception history DB 104.
The reception history table 200 stores the radio wave intensity information received from the receiver 120. The radio wave intensity information includes a transmitter ID 201, a receiver ID 202, a reception date and time 203, and an RSSI 204.
The transmitter ID 201 is transmitter identification information that uniquely identifies the transmitter 110. The receiver ID 202 is receiver identification information that uniquely identifies the receiver 120. The composite key of the transmitter ID 201 and the receiver ID 202 is the main key of each record in which individual radio wave intensity information is stored.
The reception date and time 203 indicates the date and time when the receiver 120 received a radio wave having the strength indicated by the RSSI 204.
The RSSI 204 indicates the radio wave intensity when the receiver 120 receives a radio wave.

FIG. 3 shows an example of the configuration of the transmitter table 300 stored in the transmitter DB 105.
The transmitter table 300 stores transmitter information. The transmitter information includes a transmitter ID 301, a base RSSI 302, a coefficient 303, and a witness Z coordinate 304.
The transmitter ID 301 is transmitter identification information that uniquely identifies the transmitter 110. The transmitter ID 301 is a main key of each record in which individual transmitter information is stored.
The base RSSI 302 is a radio wave intensity received when the distance between the transmitter 110 and the receiver 120 is a fixed distance (for example, 1 m).
The coefficient 303 is used when the radio wave intensity is converted into a distance.
The known Z coordinate 304 indicates the Z coordinate of the transmitter 110.
The base RSSI 302 and the coefficient 303 are obtained in advance from the actual measurement results and stored in the transmitter table 300. The base RSSI 302 and the coefficient 303 may be set to the same value for the transmitter 110 of the same model.
In addition, the known Z coordinate 304 is set in advance in consideration of the usage situation and the like. For example, when it is assumed that the transmitter 110 is carried by a general adult in his / her hand or carried in a predetermined pocket, it is considered appropriate to set 1 m to 2 m. At this time, the origin of the Z coordinate is the position of the floor of the target floor.
How to define the origin of the Z coordinate differs depending on the application and the scale of the target area to be measured. For example, in the case of positioning on the same plane and the same floor, it is appropriate to use the floor position as the origin of the Z coordinate. For the purpose of positioning a plurality of floors of a plurality of buildings and comparing the coordinates of each transmitter, it is appropriate to use the altitude described on the map as the origin of the Z coordinate.

FIG. 4 shows an example of the configuration of the receiver table 400 stored in the receiver DB 106.
The receiver table 400 stores receiver information. The receiver information includes a receiver ID 401, an X coordinate 402, a Y coordinate 403, and a Z coordinate 404.
The receiver ID 401 is receiver identification information that uniquely identifies the receiver 120. The receiver ID 401 is a main key of each record in which individual receiver information is stored.
An X coordinate 402, a Y coordinate 403, and a Z coordinate 404 are an X coordinate, a Y coordinate, and a Z coordinate in a predetermined three-dimensional coordinate system. An X coordinate 402, a Y coordinate 403, and a Z coordinate 404 indicate the position of each receiver 120.

FIG. 5 shows an example of the configuration of the positioning result table 500 stored in the positioning DB 107.
In the positioning result table 500, positioning result information indicating the positioning result of the transmitter 110 is stored. The positioning result information includes a transmitter ID 501, a reception date / time 502, an average error 503, an X coordinate 504, a Y coordinate 505, and a Z coordinate 506.
The transmitter ID 501 is transmitter identification information that uniquely identifies the transmitter 110. The reception date and time 502 indicates the date and time when the receiver 120 received the radio wave. A composite key of the transmitter ID 501 and the reception date and time 502 is a main key of each record in which individual positioning result information is stored.
The average error 503 indicates the average error of the estimated transmitter coordinates.
An X coordinate 504, a Y coordinate 505, and a Z coordinate 506 are an X coordinate, a Y coordinate, and a Z coordinate in the same three-dimensional coordinate system as the X coordinate 402, the Y coordinate 403, and the Z coordinate 404 in FIG. An X coordinate 504, a Y coordinate 505, and a Z coordinate 506 indicate the position of the transmitter 110.

FIG. 6 is a plan view of an example of an indoor area where the transmitter 110 and the receiver 120 are arranged as viewed from above. In this plan view, the position in the indoor space 601 is expressed using the X coordinate and the Y coordinate of the origin 602.
In the indoor space 601, the transmitter 110J is located at the coordinates (x _j , y _j ). The transmitter 110J is one of j transmitters.
In addition, the four receivers 120A, 120B, 120C, and 120D have coordinates (x ₁ , y ₁ ), coordinates (x ₂ , y ₂ ), coordinates (x ₃ , y ₃ ), coordinates, respectively. _(x 4, _{y 4)} is disposed at the position of.
D _1j indicates the distance between the transmitter 110 and the receiver 120A. Similarly, D _2j , D _3j , and D _4j indicate distances between the transmitter 110 and the receiver 120B, the receiver 120C, and the receiver 120D, respectively.

FIG. 7 is a front view of the same indoor 601 as FIG. 6 as viewed from the front. In this front view, the position in the indoor space 601 is expressed using the X coordinate and the Z coordinate of the origin 701.
The transmitter 110J is located at the coordinates (x _j , z _j ). The four receivers 120A, 120B, 120C, and 120D have coordinates (x ₁ , z ₁ ), coordinates (x ₂ , z ₂ ), coordinates (x ₃ , z ₃ ), coordinates (x ₄ , z ₄ ).

The positioning method in Patent Document 1 is based on the premise that the transmitter 110 and the plurality of receivers 120 are all arranged on the same XY plane. This is different from the actual three-dimensional space and does not consider the height. Therefore, when the position of the transmitter 110 is obtained on the XY plane based on the RSSI observed in the three-dimensional space by the positioning method in Patent Document 1, height information that is not taken into consideration is processed as an error.
Rather than treating this height as an error, the position is determined on the premise of a three-dimensional space similar to the real world, so that the error and the height can be distinguished and processed, and the accuracy is theoretically improved. FIG. 8 shows an example of the relationship between the three-dimensional position and distance of the transmitter 110J and the four receivers 120A, 120B, 120C, and 120D. In the space expressed as the origin 801 in the XYZ coordinate system, the transmitter 110J is located at the coordinates (x _j , y _j , z _j ), and the coordinates (x ₁ , y ₁ , z ₁ ), (x ₂ , y ₂ , The receiver 120A, the receiver 120B, the receiver 120C, and the receiver 120D are arranged at positions z ₂ ), (x ₃ , y ₃ , z ₃ ) (x ₄ , y ₄ , z ₄ ), respectively.

FIG. 9 shows an example of a flow of radio field intensity information storage processing for storing radio field intensity information transmitted from each receiver 120 in the reception history DB 104.
First, the receiving unit 103 receives radio wave intensity information from each receiver 120. (S901). Next, the reception processing unit 102 stores the received radio wave intensity information in the reception history DB 104 (S902).

FIG. 10 shows an example of the flow of position estimation processing for estimating the position of the transmitter at a certain point of time based on the reception history and storing positioning result information indicating the estimated position in the positioning DB 107.
First, the positioning processing unit 101 extracts a transmitter ID 201 from radio wave intensity information received between reception time = t + Δt and t−Δt, which is stored in the reception history DB 104 in order to extract the transmitter 110 to be processed. Are acquired without superimposition, and the list of the acquired transmitter IDs 201 is stored in the array list (S1001).

Next, the positioning processing unit 101 repeatedly performs steps S1003 to S1007 for each acquired transmitter ID (S1002). At the time of repetition, the address number A of the array list is incremented from 0 to (number of array lists−1). If the number of elements of the array list [A] is 2 or less (that is, 2 or less receivers 120 have received radio waves from the transmitter 110 with the address number A) (S1003: No), the positioning processing unit 101 performs step The process returns to S1002.
When the number of elements of the array list [A] is 3 or more (that is, 3 or more receivers 120 that have received radio waves from the transmitter 110 with the address number A) (S1003: Yes), the positioning processing unit 101 receives the reception time Among the radio field intensity information received between t = Δt and t−Δt, all the radio field intensity information of transmitter ID 201 = array list [A] is acquired from the reception history DB 104 (S1004). The positioning processing unit 101 acquires all receiver information having the receiver ID 401 that matches the receiver ID 202 included in each acquired radio wave intensity information from the receiver DB 106 (S1005). At the same time, the positioning processing unit 101 acquires the transmitter information of the transmitter ID 301 = array list [A] from the transmitter DB 105 (S1006).
Next, for each receiver 120, the positioning processing unit 101 determines the observation distance by the following equation based on the RSSI 204 included in the radio wave intensity information and the base RSSI 302 and the coefficient 303 included in the transmitter information acquired in step S1005. d _ij is obtained (S1007).

Here, RSSI is RSSI 204 included in the radio wave intensity information. Further, a and b are a base RSSI 302 (RSSI value at a distance of 1 m) and a coefficient 303 included in the receiver information, respectively, which are obtained in advance from an actual measurement result and stored in the transmitter DB 105.
Then, the positioning processing unit 101 determines the position of the transmitter 110J based on the position of the receiver 120 (X coordinate 402, Y coordinate 403, Z coordinate 404) and the observation distance _dij included in the receiver information acquired in step S1004. The position is estimated (S1008). Specifically, the inter-coordinate distance D _ij between the position (x _j , y _j , z _j ) of the transmitter 110J to be estimated and the position (x _i , y _i , z _i ) of the receiver 120 is expressed by the following equation. .

At this time, the position of the transmitter 110J that minimizes the sum of squares of the difference between the observation distance d _ij between the transmitter 110J and the receiver 120 and the inter-coordinate distance D _ij may be obtained. This can be obtained by solving the following least squares method.

Since the above equation is non-linear, it is generally solved by an iterative process such as the Newton method, the steepest descent method, or the Levenberg-Markert method. Description of each method is omitted.
There are three variables to be estimated here: x _j , y _j , and z _j . By setting the height z _j of each transmitter 110 to a known constant, the estimation result in the positioning processing unit 101 can be stabilized and the amount of calculation can be reduced. Specifically, the positioning processing unit 101 uses a known Z coordinate 304 stored in the transmitter DB 105 as a known height, and the height z _j of each transmitter 110 = the known Z coordinate 304 described above. The three-dimensional coordinates of each transmitter 110 are estimated by performing the above iterative process. In addition, the positioning processing unit 101 performs the above-described iterative process as the initial value of the height z _j of each transmitter 110 without estimating the known Z coordinate 304 as a constant, and estimates the three-dimensional coordinates of each transmitter 110. May be. These are particularly effective when the Z coordinate of the transmitter is fixed or substantially fixed and the number of receivers 120 is small.
When the known Z coordinate 304 is not defined, the above-described iterative process is performed by setting the initial value of the height z _j of each transmitter 110 to 0, and the three-dimensional coordinates of each transmitter 110 are estimated.

  Further, by using three receivers 120, the positioning processing unit 101 can obtain these variables. However, if the number of receivers 120 received is small, the result may be unstable. Therefore, by using four or more receivers 120, it is possible to improve the estimation accuracy of the coordinates of the transmitter 110 in the positioning processing unit 101 as compared to the case of using three receivers 120.

Next, as shown in the following equation, the positioning processing unit 101 takes the square root of the sum of squares of the error between the observation distance d _ij and the inter-coordinate distance D _ij , and obtains the average error as the average error. The positioning processing unit 101 uses this average error as an index for judging the accuracy of the estimated position (x _j , y _j , z _j ) of the transmitter 110J.

Finally, the positioning processing unit 101 stores the estimated positioning result information of the transmitter 110J (transmitter ID 501, reception date / time 502, average error 503, X coordinate 504, Y coordinate 505, Z coordinate 506) in the positioning DB 107 ( S1009).
Step S1006 is an example of an observation distance calculation step realized by the observation distance calculation means of the present invention, and step S1007 is an example of a transmitter position estimation step realized by the transmitter position estimation means of the present invention.

  As described above, according to the present invention, it is possible to prevent an elevation difference from the same plane in a plurality of receivers from being mixed into a positioning error, and to perform positioning with higher accuracy.

DESCRIPTION OF SYMBOLS 100 ... Transmitter positioning apparatus, 101 ... Positioning processing part, 102 ... Reception processing part, 103 ... Reception part, 104 ... Reception history DB, 105 ... Transmitter DB, 106 ... Receiver DB106, 107 ... Positioning DB107, 110 ... Transmission 120, receiver, 130, network, 200, reception history table, 300, transmitter table, 400, receiver table, 500, positioning result table

Claims (5)

A radio wave transmitter positioning system that receives radio waves transmitted from a moving transmitter by a plurality of receivers and obtains the position of the transmitter from the radio wave intensity received by each receiver,
A receiver table storing receiver information including the three-dimensional coordinates of the position of each receiver;
An observation distance calculation means for obtaining an observation distance between each receiver and the transmitter based on the radio field intensity received by each receiver;
Three-dimensional coordinates of the position of the transmitter based on the observation distance obtained by the observation distance calculation means and the three-dimensional coordinates of the position of each receiver included in the receiver information stored in the receiver table Transmitter position estimation means for obtaining
A radio wave transmitter positioning system comprising: A transmitter table in which transmitter information including a known height of the transmitter is stored;
The transmitter position estimating means uses a known height of the transmitter included in the transmitter information stored in the transmitter table as one of the three-dimensional coordinate values of the transmitter position. As the initial value of the height, the other two coordinate values are obtained.
The radio wave transmitter positioning system according to claim 1.   3. The radio wave transmitter positioning system according to claim 1, wherein the number of the receivers that have received a signal from a transmitter to be positioned in a certain period is three or more. A radio wave transmitter positioning device used in the radio wave transmitter positioning system according to any one of claims 1 to 3,
A receiver table storing receiver information including the three-dimensional coordinates of the position of each receiver;
An observation distance calculation means for obtaining an observation distance between each receiver and the transmitter based on the radio field intensity received by each receiver;
Three-dimensional coordinates of the position of the transmitter based on the observation distance obtained by the observation distance calculation means and the three-dimensional coordinates of the position of each receiver included in the receiver information stored in the receiver table Transmitter position estimation means for obtaining
A radio wave transmitter positioning device comprising: A radio wave transmitter positioning method in which radio waves transmitted from a moving transmitter are received by a plurality of receivers, and the position of the transmitter is obtained from the radio wave intensity received by each receiver,
An observation distance calculation step for obtaining an observation distance between each receiver and the transmitter based on the radio wave intensity received by each receiver;
Based on the observation distance obtained in the observation distance calculation step and the three-dimensional coordinates of the position of each receiver included in the receiver information stored in the receiver table, the three-dimensional coordinates of the position of the transmitter are obtained. A desired transmitter position estimating step;
A radio wave transmitter positioning method comprising:

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